Device for quickly tracing circles of given diameters



N. B. COSTOVICI.

C DEVICE FOR QUICKLY TRACING CIRC'LES 0F G'LVN DIAMETEHS.

APPLgcATIoN FILED' OCT. 27. 1917.

1,341,457. Patented May 25, 1920.

| l O/ o o o o o e Q 4 y? a 1o 12 14 16 la a 22 24E @WMM/w z mw@ BM@ @mm1 NICOLAS BASILE COSTOVICI, 0F LAUSANNE, SWITZERLAND.

DEVICE FOR QUICKLY TRACING CIRCLES' OF GIVEN DIAMETERS.

j Specification of Letters Patent.

Patented May 25, 1920.

Application led October 27, 1917. Serial No. 198,747.

To all whom t may concern:

Be it known that l, NicoLAs BASILE Cos'rovro, a subject of the- King of Rumania, and residing at Lausanne, Switzerland, have invented a certain new and useful Improved Device for Quickly Tracing Circles of Given Diameters, of which the following is a speciication.

The object of my present` invention is a device for quickly tracing circles of a given diameter. Said device comprises a ruler provided with perforations whereof one serves as a guide for a center point which is passed through the ruler into a suitable drawing surface and another as a guide for a drawing pencil or pen in such a manner that by swinging the ruler around the center point a circle ot' a given diameter may be traced on the drawing' surface by means of said drawing pencil or pen. My device is further provided with a holding bar for the center point whereby the latter is held from the outside of the largest possible circle to be drawn with the device in such a way, that no hole will be made by the point in the drawing surface.

The drawing represents one embodiment ofmy invention.

Figure l is partly a section, partly a side elevation of the device in its working position.

Fig. 2 is a side elevation of the ruler incased within the holder.

Fig. 3 is a section on line III- III in Fig. l.

Fig. 4 is a section 0n line IV-IV in Fig. l.

Fig. 5 is a section on line V-V of Fig. 2 and Fig. G is an end view of the ruler as seen from the left in Fig. l.

A flat'ruler 2 marked on one of its side edges with a scale and preferably made of transparent material, such as Celluloid. is provided on its longitudinal center line with a number of perforations 2 at a certain distance apart, and with a slot 5 cut near the one end of it on the said center line. Above this slot 5 there is provided a slide piece 4 made adjustable along a small scale 4 by means of a micrometric screw 3 the free face end of which is 'marked with a scale providing for a fine adjustment of the slide as indicated by the hand`4 fixed to the slide. The slide has a ne hole 4', for receiving a needle l serving as center point when tracing circles with the device. In the working position of the device (Fig. l) this center point is adjustably held at its upper end within a perforation ola sleeve 6 by means of a set screw 7. The sleeve 6 is fitted with a laterally projecting ear 8 wherewith it is held between the side walls of a fiat hollow bar 9 of U shaped cross section. This bar 9, open along its whole bottom side, is eX- tended in width at its opposite end with regard to the sleeve 6 and is of a greater length thanthe ruler 2 so that the latter may be incased within it as shown in Fig. 2, that is to say, the bar 9 serves as casing for the ruler when not in use. Besides, owing to this greater length of bar 9, it is possible to hold the center point from the outside of the greatest possible circle to be drawn with the device without any perceptible downward pressure, so that no hole will be produced on the drawing surface however many concentric circles may be drawn thereon. In order to prevent any hole from being made in said surface it is advisable to give a strongly conical shape to the said center point.

The use of said device is as follows:

The center point clamped fast within sleeve 6 is passed as described above into the hole 4 of slide piece 4 while the ruler 2 is laid on the drawing surface and the bar 9, held with4 one hand, is set with its downwardly extended edge on the said drawing surface. With the other hand a drawing instrument such as a pencil or a pen is inserted into one of the holes 2 with its point bearing against the drawing surface. By swinging by means ot the drawing instrument the ruler around the center point a circle will be traced on the drawing surface of a diameter corresponding to the distance betweenv center-point and pencil. By inserting the latter into another hole 2 or by moving the slide 4 by means of the micrometric screw another circle, concentric with the first, may be drawn, when swinging the ruler around the center point. In such a manner as many concentric circles as desired may be drawn.

l/Vith the device as represented in the drawing circles of a given diameter may be drawn at once without first measuring on a scale. so that Compasses, ruler and scale are combined into one instrument. By using Compasses errors are easily made when measuring the diameters of circles. This is hardly possible with the device as described a bar of greater length than the said ruler 15 and shown, as the corresponding diameters are marked in numbers beside each hole 2. The instrument may be builtup of any suitable transparent or non-transparent material, such as of Celluloid', metal, wood or the like.

I claim- A device for tracing circles of a given diameter comprising a ruler bearing a scale on one of its side edges and having holes along its longitudinal center-line for the insertion of a drawing instrument, a center point adapted to enter one of said holes, and

and having a downwardly extended edge adapted to rest on a drawing surface and also a freely projecting end, a sleeve adjustable therein forming a support for said center point, the said bar being shaped so as to receive the said ruler when not in use.

In testimony whereof I aihx my signature `in the presence of two witnesses.

NICOLAS BASILE COSTOVICI. 

